Question

Program using java !!

Create two files, file1.csv and file2.csv

Write the following information in file1.csv:

Apple 1.69 001

Banana 1.39 002

Write the following information in file2.csv:

Apple 1.69 001

Carrot 1.09 003

Beef 6.99 004

You have two files, both of the two files have some information about products: • Read these two files, find out which products exist in both files, and then save these products in a new file. You can use the two files you created in Lab 1 as an example. If you use file1.csv and file2.csv from Lab 1, the result file will be:

•Result file:

Apple 1.69 001

8.5.0

Answer 1

Java.io.PrintWriter class

this class is used to  Prints formatted representations of objects in a text-output stream.

used to write line from other file as a filestream.

Java.io.BufferedReader Class in Java

Reads text from a character-input stream as a buffering characters so as to provide as a text reading in a line mod

code

//file1.csv contains data 
/*  Apple 1.69 001
    Banana 1.39 002   */
//file2.csv contains data 
/*
Apple 1.69 001
Carrot 1.09 003
Beef 6.99 004
*/    
//file3.csv contains data 
/*
Apple 1.69 001
*/
//file name check.java 
import java.io.*; 
public class check
{ 
  public static void main(String[] args)throws Exception 
  { 
  //BufferedReader to read file as a stream
  //br.readLine is ude to read line from file as string 
 BufferedReader br1 = new BufferedReader(new FileReader("file1.csv")); 
  BufferedReader br2 = new BufferedReader(new FileReader("file2.csv")); 
  String st; 
  //print file1 data 
  System.out.println("---------------------");
   System.out.println("File1 contains DATA : ");
   System.out.println("---------------------");
  while ((st = br1.readLine()) != null) 
    System.out.println(st); 
    //print file2 data 
   System.out.println("---------------------");
   System.out.println("File2 contains DATA : ");
   System.out.println("---------------------");
    while ((st = br2.readLine()) != null) 
    System.out.println(st); 
    BufferedReader br11 = new BufferedReader(new FileReader("file1.csv")); 
  BufferedReader br22 = new BufferedReader(new FileReader("file2.csv"));
    String line1,line2;
    //   PrintWriter to create new file as file3.txt
    PrintWriter pw = new PrintWriter("file3.csv");
    line1 = br11.readLine();
    line2= br22.readLine();
    System.out.println("---------------------");
   System.out.println("File3 contains DATA : ");
   System.out.println("---------------------");
   //code to check line1 and line2 have same string 
   //line1.equals(line2) return true if they are the same string
    while(line1!=null && line2!=null)
    {
    if(line1.equals(line2))
    {System.out.println(line1);
    pw.println(line1);
    } 
    line1 = br11.readLine();
    line2= br22.readLine();
    }
     pw.flush(); 
          
        // closing resources 
        br11.close(); 
         br22.close(); 
         br1.close(); 
         br2.close(); 
        pw.close();
  }
  }
  

Steps to run

Step 1 : write file name check.java

step2 : type javac check.java in the terminal for compile

step3 : type java check to run the file

Note

avoid writing extra line as null values means write line up to which required line don't give extra line while creating

your file file1.csv and file2.csv other wise it will givw error as null pointer exception.

output is below;